Embodiments of the invention concern a crate or container for accommodating products, more specifically, embodiments of the invention concern a plastic crate that is provided for receiving and/or for transporting foods, like fruits, vegetables, meat and the like.
Crates for storing and transporting products such as fruits and vegetables are widely used in the market. Such crates are light and stable which makes them suitable for bringing the crops from the field to the customer. For example, for tropical fruits like bananas, it is common to harvest the crop while it is still unripe and pack it into the crates for subsequent shipping and transportation. On this journey, the fruits have time to ripen. Also, other fruits like apples or the like, or vegetables like lettuce or the like, but also meat or eggs may be put into the crates at the producers site and transported using such crates.
Before the transport, the filled crates are usually stacked on top of each other and arranged side by side on two pallets and the pallets, as a whole, are then transported to respective transport facilities. Often, a specific cross-stacking technique is used, for example, a “5-down configuration”. In such a 5-down configuration, five crates are arranged adjacent to each other into a rectangular array, such that two of them form a row in the length direction and the other three form a row in the width direction. One problem with such kind of arrangement is that upon stacking the crates in this way, the three crates forming the row in the width direction abut with their shorter end walls the longer side walls of the two crates forming the row in the length direction. Thus, a force acting onto the lateral side walls of the crate arrangement in the length direction is high, especially in the central area of the side walls of the crates arranged in the length direction. This may result in a damaging of the crates during the transport or during stacking.
The above described crates may be plastic crates that comprise opposing end walls and opposing side walls extending from a bottom having a generally rectangular shape. The crates may also be formed from other materials, like wood, carton or the like. The crates may be so-called foldable crates, which means that the end walls and the side walls can be folded downward into the direction of the bottom. This allows the transport of empty crates in their folded state, for example to the fields, where the crop is harvested and directly put into the respective crates. This allows for shipping a high number of folded crates, using a minimum amount of transport capacity, thereby bringing the folded crates to the desired locations in an economical way. There are crates of different heights, i.e. some crates have walls extending from the bottom by a first distance, whereas others extend upward by a second distance that may be more than the first distance. The height of the crates, when being unfolded, depends on the products to be received therein and transported. The structure of the crate having the foldable walls may be such that the side walls when being folded downward onto the bottom may overlap. In such a case, to obtain a minimum possible height, conventional crates require a specific sequence of folding the respective wall portions. For example, first of all, the two end wall portions are to be folded onto the bottom and then a first of the two side walls is folded downward to rest on the folded-down end walls and then a second of the side walls is folded down afterwards. The respective side walls are configured in such a way that a minimum height of the folded crate is obtained without any parts extending beyond this height.
However, this approach is disadvantageous as it requires the user of a crate to be aware of how the crate is to be folded, i.e., the respective wall portions need to be folded in the correct way, otherwise the minimum height is not obtained and, in addition, elements of the wall portions may extend beyond the minimum height, thereby avoiding proper stacking of the folded crates. One solution to this problem is to provide a projection on the edge of the bottom extending upwardly from the bottom by a predefined distance, thereby ensuring that independent of the way the two side walls are folded, even in the “worst case”, none of the parts of the side walls extend above the upper end of the projection. While this solves the problem regarding parts extending beyond the height of the folded crate, it increases, at the same time, the height of the folded crate and thereby limits the overall number of folded crates that can be stacked and shipped. While this may seem a minor problem when looking only at a single crate, one has to consider the situation that a high number of such crates is folded and shipped by being placed on respective pallets and the projection having the increased height as mentioned above, may result in a loss of transport capacity of about 15%.
The crates described above, which are foldable, further comprise a locking mechanism that ensures a secure connection of the side walls and the end walls in the unfolded state of the crate. At the same time, an easy to handle mechanism must be provided for releasing the latch when it is desired to fold the crate after all products have been removed and the crate is to be shipped back to the supplier, for example, for cleaning. Crates having foldable walls therefore comprise release mechanisms that act onto the latch elements provided for releasing the latch and thereby allowing folding downward the respective side walls. For example, the side walls may comprise respective receptacles formed at a lateral edge thereof, a lateral edge is being adjacent to the end walls. In the end walls movable latch mechanisms may be provided, for example, a hook that is biased into a downward direction and engages with the receptacle in the side wall upon bringing the respective walls into their upright position. For example, when moving a side wall from the bottom position to the upright position, the hook is lifted upon passing the elements of the side wall and then, due to the downward bias, the hook is received in the receptacle. For releasing the latch by means of the release mechanism, the hook is lifted, so that the latch elements are disengaged and the side wall can be folded downward into the direction of the bottom again.
These mechanisms provide an easy to handle way for unfolding the crate, however, the mechanisms, in general, are provided such that same can be actuated any time the crate is in the unfolded state. This is disadvantageous as it also allows actuating the release mechanism when a plurality of crates are stacked, for example on a pallet. In such a situation due to a shock or to an erroneous handling a latch mechanism of one or more of the crates inside the stack may be actuated, thereby unlocking the respective wall element, making the stack as a whole unstable. In the worst case, this may result in the collapse of the stack because one or more of the crates inside the stack may no longer provide the required stability for supporting the crates stacked on top thereof.
As mentioned above, the crates may be used for transporting foods, like vegetables, fruits and meat or the like. These products may require cooling and it is therefore desired to provide to the interior of the crate a cooling liquid, like ice-water or the like ensuring that the goods stay fresh and/or at a desired temperature. While the crates, in general, have openings in the side walls and the bottom for allowing the circulation of air, these openings may not be sufficient to allow a sufficient flow of cooling liquid into the interior of the crate, for example, when using ice-water, it may well be that ice particles are within the fluid stream which cannot pass the holes provided for air ventilation and, that may actually block the holes, thereby avoiding that the liquid reaches the interior of the crate.